Webrtc数据交互详情

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Webrtc数据交互详情

交互详情

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sequenceDiagram
participant A as 用户A
participant WS as WS
participant B as 用户B

A->>WS: 1. 创建offer并发送 sdp type:offer
WS->>B: 2. sdp type:offer
B->>WS: 3. sdp type:answer
WS->>A: 4. sdp type:answer
A->>WS: 1. 发送candidate
WS->>B: 2. 发送candidate
B->>WS: 3. 发送candidate
WS->>A: 4. 发送candidate
B->>A: 连接

交互的数据

1 创建offer并发送

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{"type":"offer","sdp":"v=0\r\no=- 72532 0 IN IP4 127.0.0.1\r\ns=sipsorcery\r\nt=0 0\r\na=group:BUNDLE 0\r\nm=video 9 UDP/TLS/RTP/SAVP 96 100\r\nc=IN IP4 0.0.0.0\r\na=ice-ufrag:SEFW\r\na=ice-pwd:ZWIYQSXNKGKSEUCBULXIQQCQ\r\na=fingerprint:sha-256 7B:8E:55:E3:27:F2:B3:30:E9:2C:A0:87:E2:C9:1F:70:F6:A7:52:97:F6:F6:04:4B:F0:2A:04:87:FD:CA:9E:B7\r\na=setup:actpass\r\na=candidate:950637637 1 udp 2113937663 192.168.3.56 62710 typ host generation 0\r\na=ice-options:ice2,trickle\r\na=mid:0\r\na=rtpmap:96 VP8/90000\r\na=rtpmap:100 H264/90000\r\na=fmtp:100 packetization-mode=1\r\na=rtcp-mux\r\na=rtcp:9 IN IP4 0.0.0.0\r\na=end-of-candidates\r\na=sendrecv\r\na=ssrc:1819341444 cname:6fef90ad-0e6b-4af4-9220-377c2faf01d8\r\n"}

2 响应

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{"type":"answer","sdp":"v=0\r\no=- 8100819546663100148 2 IN IP4 127.0.0.1\r\ns=-\r\nt=0 0\r\na=group:BUNDLE 0\r\na=msid-semantic: WMS 0eb90fdc-f221-409a-8cc2-10015551f1d1\r\nm=video 9 UDP/TLS/RTP/SAVP 96 100\r\nc=IN IP4 0.0.0.0\r\na=rtcp:9 IN IP4 0.0.0.0\r\na=ice-ufrag:Kz3X\r\na=ice-pwd:ci0C3HqUXi/oTbiOqzjxdNKF\r\na=ice-options:trickle\r\na=fingerprint:sha-256 4D:2B:B6:60:B9:F2:C5:9C:D9:7C:DC:7C:DA:E4:1A:A0:B6:79:D7:9D:66:9A:99:05:09:56:A4:43:FF:B3:48:E3\r\na=setup:active\r\na=mid:0\r\na=sendrecv\r\na=msid:0eb90fdc-f221-409a-8cc2-10015551f1d1 c32f714c-b627-4313-be6d-15fbbc7d8656\r\na=rtcp-mux\r\na=rtpmap:96 VP8/90000\r\na=rtpmap:100 H264/90000\r\na=fmtp:100 level-asymmetry-allowed=1;packetization-mode=1;profile-level-id=42e01f\r\na=ssrc:2948904417 cname:ufqrpgnhfhKdMI5c\r\na=ssrc:2948904417 msid:0eb90fdc-f221-409a-8cc2-10015551f1d1 c32f714c-b627-4313-be6d-15fbbc7d8656\r\n"}

3 并发送candidate

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{"candidate":"candidate:388572998 1 udp 2113937151 bd043a02-be83-461c-84d3-6ab8d12290c5.local 62712 typ host generation 0 ufrag Z/Ju network-cost 999","sdpMid":"0","sdpMLineIndex":0,"usernameFragment":"Z/Ju"}

SDP数据

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v=0
o=- 72532 0 IN IP4 127.0.0.1
s=sipsorcery
t=0 0
a=group:BUNDLE 0
m=video 9 UDP/TLS/RTP/SAVP 96 100
c=IN IP4 0.0.0.0
a=ice-ufrag:SEFW
a=ice-pwd:ZWIYQSXNKGKSEUCBULXIQQCQ
a=fingerprint:sha-256 7B:8E:55:E3:27:F2:B3:30:E9:2C:A0:87:E2:C9:1F:70:F6:A7:52:97:F6:F6:04:4B:F0:2A:04:87:FD:CA:9E:B7
a=setup:actpass
a=candidate:950637637 1 udp 2113937663 192.168.3.56 62710 typ host generation 0
a=ice-options:ice2,trickle
a=mid:0
a=rtpmap:96 VP8/90000
a=rtpmap:100 H264/90000
a=fmtp:100 packetization-mode=1
a=rtcp-mux
a=rtcp:9 IN IP4 0.0.0.0
a=end-of-candidates
a=sendrecv
a=ssrc:1819341444 cname:6fef90ad-0e6b-4af4-9220-377c2faf01d8

可以看出

在SDP阶段，双方交换了各种支持的编码和IP

回发

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v=0
o=- 8100819546663100148 2 IN IP4 127.0.0.1
s=-
t=0 0
a=group:BUNDLE 0
a=msid-semantic: WMS 0eb90fdc-f221-409a-8cc2-10015551f1d1
m=video 9 UDP/TLS/RTP/SAVP 96 100
c=IN IP4 0.0.0.0
a=rtcp:9 IN IP4 0.0.0.0
a=ice-ufrag:Kz3X
a=ice-pwd:ci0C3HqUXi/oTbiOqzjxdNKF
a=ice-options:trickle
a=fingerprint:sha-256 4D:2B:B6:60:B9:F2:C5:9C:D9:7C:DC:7C:DA:E4:1A:A0:B6:79:D7:9D:66:9A:99:05:09:56:A4:43:FF:B3:48:E3
a=setup:active
a=mid:0
a=sendrecv
a=msid:0eb90fdc-f221-409a-8cc2-10015551f1d1 c32f714c-b627-4313-be6d-15fbbc7d8656
a=rtcp-mux
a=rtpmap:96 VP8/90000
a=rtpmap:100 H264/90000
a=fmtp:100 level-asymmetry-allowed=1;packetization-mode=1;profile-level-id=42e01f
a=ssrc:2948904417 cname:ufqrpgnhfhKdMI5c
a=ssrc:2948904417 msid:0eb90fdc-f221-409a-8cc2-10015551f1d1 c32f714c-b627-4313-be6d-15fbbc7d8656